Upload a video file and re-time it to 60 frames per second. Changing the frame rate re-encodes the video, so longer files take a while.
Your file never leaves your device. All processing happens right in your browser, and nothing is uploaded to a server.
The tool re-encodes your video at 60 fps by duplicating frames from lower-rate sources. The result satisfies any spec demanding 60 fps. What it does not do is invent new motion: 30 fps footage will look like 30 fps motion in a 60 fps wrapper.
Mixed timelines standardizing on 60 fps, platforms and tools that hard-require it, and concatenating clips where frame rates must agree before a merge.